Recently, development of medical materials capable of performing contrast X-ray radiography has been demanded.
For example, a hollow fiber or a hollow monofilament containing a contrast agent in the hollow portion thereof has been proposed. It has been proposed to use the hollow fiber or the hollow monofilament as formed into a braided cord shape, or to obtain various medical materials such as pins in bone fixation materials by chopping the hollow fiber or the hollow monofilament into short fibers (JP2000-336521A).
JP2002-266157A describes an X-ray sensitive fiber composed of a thermoplastic resin containing a radiopaque agent, and also describes the use of this X-ray sensitive fiber as woven into part of surgical gauze or the like.
By using X-ray contrasting threads in part of the fibers constituting the gauze fabric, such surgical gauze is made discernible when left in the body. However, such surgical gauze left in the body is frequently made hardly accessible by contrast X-ray radiography due to the various organs and body fluids. Accordingly, as the X-ray contrasting thread, threads having higher contrast capability are demanded. Further, surgical gauze may be brought into direct contact with the skin or the organ of an affected part or the like, and hence surgical gauze is demanded to have flexibility exhibiting soft texture.
However, the fiber proposed in JP2000-336521A uses general-purpose polymers such as nylon and polypropylene. Therefore, the obtained hollow fibers lack in flexibility and cause inconvenience when used as woven into part of surgical gauze or the like.
The fiber described in JP2002-266157A has a moderate content of a radiopaque agent, and hence has not yet attained a sufficient X-ray contrast performance.
JP2004-162239A proposes a monofilament, with a styrene elastomer used therein, allowing contrast X-ray radiography. This monofilament is capable of improving the operability through specifying the resin hardness. However, with the hardness described in JP2004-162239A, no sufficient flexibility is obtained. Therefore, the monofilament proposed in JP2004-162239A is not suitable for being woven into part of surgical gauze or the like.